name this gearbox

Gearbox?

Can't see much in the small photo. Front freewheel assembly looks home made.
 
Need a close-up....looks home made. Think I'd put a chain guard on that one....seriously.
 
Are you sure it spins the wrong way? I wasn't able to find any written info on the box.

If there's only two gears, it reverses engine direction and spins correctly. If there's an idler gear, it spins the wrong way.

Here's hoping someone can utilize this box.

A 5:1 pocketbike tranny is hard to beat.
 
I also vote for the scooterparts gearbox.
I have built several motorized bikes with the same setup.
The engine is spinning the wrong way to power the bicycle in a forward direction.
The reversing gearbox corrects this as well as providing 5 to 1 reduction so you dont need a 140 to 200 tooth crank sprocket
 
I take it back. It is neither the 5:1 gearbox nor the 7:1 gearbox.

These gearboxes bolt directly onto the engine bellhousing on the opposite side of the pullstart. In the picture, the chain links to a sprocket UNDER the engine.....on the pullstart side of the engine.

THEREFORE, I'm guessing it is a JACKSHAFT, bolted under the engine and onto the bike's frame. The other side of the jackshaft is probably connected to a clutch-driven engine sprocket/pulley like this:

http://cgi.ebay.com/47cc-49cc-Pocke...287?pt=LH_DefaultDomain_0&hash=item518b0dfb3f

If it IS a jackshaft, then the 5:1 gearbox is definitely NOT bolted onto this engine. The jackshafts' sprockets, combined with the chainring sprocket is not enough to utilize the engine to its best potential.

Just my opinion...
 
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